#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=2e3+100;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
LL a[maxn],tot=0;
LL val[maxn];
int main(void)
{
  cin.tie(0);std::ios::sync_with_stdio(false);
  LL n,m;cin>>n>>m;
  for(LL i=1;i<=n;i++) cin>>val[i];
  LL sum=0;
  for(LL i=1;i<=m;i++){
    LL x;cin>>x;
    bool flag=1;
    multiset<LL>s;
    for(LL j=tot;j>=1;j--){
        if(s.count(a[j])) continue;
        s.insert(a[j]);
        if(a[j]==x){
            flag=0;
            a[++tot]=x;
            break;
        }
        else sum+=val[a[j]];
    }
    if(flag==1) a[++tot]=x;
  }
  cout<<sum<<"\n";
return 0;
}
